Researchers create conveyer belt for magnetic flux vortices in superconductors

Mar 12, 2006

If blown up in size, it would not have a chance in the car factory, but the microscopic conveyer belt built by Simon Bending's team in the Department of Physics at the University of Bath and collaborators in Japan and the USA, could just be the next big thing for improving devices relying on the elusive properties of superconductors (Nature Materials, Advanced Online Publication March 12 2006). It's not your standard rubber band on cylinders though – it moves in an erratic way, a quick jolt to the left, a smooth slide to the right. Who would want to be on such a thing?

Tiny swirls of electric currents, it seems. These so-called vortices are the closest things to 'hurricanes' for the superconducting researcher and engineer, and no less threatening. That's because the zero resistance to current flow in even the best superconductors breaks down once vortices enter and start to move around. Their motion can also lead to unpredictable 'noise' if it takes place near the most sensitive regions of superconducting devices. Bending has now shown that it is possible to move vortices around inside a superconductor almost at will using his shaky conveyer belt. In this way they can either be removed entirely or at least left where they cause the least harm.

The asymmetry in its movement is the key to success, since it ensures that the vortices all move in one direction, even though the belt itself moves back and forth. The reason behind this is that the vortices can only follow along during the smooth slides to the right, and not during the jolts in the other direction. The conveyer belt thus acts in some sense as a rectifier, just like the diodes known from electronics.

The mind-boggling part is now that the conveyer belt is assembled out of a line of vortices itself, created and controlled by a time-varying magnetic field. As the researchers show, this way "bad" vortices can be completely removed out of targeted regions inside the superconductor, and the vortices induced to create the conveyer belt can be readily removed from the sample afterwards if need be.

Using this trick, superconducting devices, such as filters for telecommunications or ultra-sensitive magnetic field probes, could be improved by removing vortices - naturally caused by the earth's magnetic field or man-made disturbances – from regions critical to device operation.

Source: University of Bath

Explore further: A new approach to on-chip quantum computing

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

A new approach to on-chip quantum computing

1 hour ago

Commercial devices capable of encrypting information in unbreakable codes exist today, thanks to recent quantum optics advances, especially the generation of photon pairs—tiny entangled particles of light. ...

Hide and seek: Sterile neutrinos remain elusive

22 hours ago

The Daya Bay Collaboration, an international group of scientists studying the subtle transformations of subatomic particles called neutrinos, is publishing its first results on the search for a so-called ...

Novel approach to magnetic measurements atom-by-atom

Oct 01, 2014

Having the possibility to measure magnetic properties of materials at atomic precision is one of the important goals of today's experimental physics. Such measurement technique would give engineers and physicists an ultimate ...

User comments : 0